#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
ll N;


int main(){

    ll N;
    cin >> N;
    ll X = N;
    ll ans = 0;
    while(X > 1){
        if(X % 2 == 1){
            X--;
            
        }else{
            X /= 2;
        }
        
        ans++;
    }
    cout << ans << endl;



}